JPH10251519A - Silicon composition, pattern-forming method using the composition and production of electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silicon composition capable of forming a fine SiO2 pattern having high Tg and excellent heat resistance in high precision by alkali development and exhibiting excellent transparency in deep UV region by using a specific silicon compound. SOLUTION: This composition contains (A) a silicon compound having hydrogen silsesquioxane structure, (B) a compound decomposable with an acid to form an acid and (C) a compound generating an acid by the irradiation with light. The composition preferably contains a silicon compound having a hydrogen silsesquioxane structure expressed by the formula (R<1> is a group decomposable with an acid to form an acid; (m) and (n) are each a natural number) and the component C. The component A is e.g. a hydridosilane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a silicon composition for forming a silicon-based oxide film pattern, a pattern forming method using the same, and a method for manufacturing an electronic component.

[0002]

BACKGROUND ART Hydrogen silsesquioxane SiO ₂ becomes by heating, a silicon-based resin oxide film is formed by coating film, SiO ₂ film obtained, for example, oxide film or a protective film in a semiconductor device Used as In some cases, it is required to form a contact hole by patterning an insulating film formed on a wiring. For example, an organic resist is used to form SiO _{2 in the} following steps.
Patterning of the film is performed. That is, a resist is applied on the formed SiO ₂ film to form a resist film, and a predetermined region of the resist film is irradiated with light through a mask to perform exposure. Next, the resist film is developed with an alkaline aqueous solution to obtain a patterned resist film. Using this resist pattern as a mask,
By etching the O ₂ film, a patterned SiO ₂ film is obtained. After the patterning of the SiO ₂ film in this manner, a step of removing the resist pattern is required. Therefore, when the SiO ₂ film pattern is formed using the resist, the process is inevitably complicated.

[0003] The use of a photosensitive silicon composition eliminates the need for a resist coating step and the like, so that the steps can be shortened. As such a silicon composition, a composition containing hydrogen silsesquioxane and a radical generator represented by peroxide is disclosed in US Pat. No. 6,888,418 and JP-A-5-204161. A negative pattern can be formed by exposing a predetermined region of a coating film containing this composition to light and developing with an organic solvent. However, in recent years, development with an organic solvent tends to be avoided due to environmental problems, and development with an easily processable alkaline aqueous solution has been demanded.

On the other hand, as the memory capacity of the semiconductor increases, the miniaturization of the semiconductor wiring is progressing, and the shorter wavelength A
A resist for exposure with an rF excimer laser (wavelength 193 nm) is required. The organic polymer contained in the resist used for patterning the SiO ₂ film as described above generally has a large UV absorption at 193 nm.
For this reason, it is difficult to transmit light to the lower layer of the resist film, and a fine resist pattern cannot be formed with high resolution. As a result, a SiO ₂ film patterned with desired dimensions cannot be obtained.

[0005]

As described above, in obtaining a patterned SiO ₂ film, when a resist is used, not only the process becomes complicated, but also the exposure can be performed with high accuracy even by using an ArF excimer laser. SiO
It is difficult to pattern the _two films to desired dimensions.

On the other hand, the use of a photosensitive silicon composition is not preferred because an organic solvent is used for development.

[0007] In view of these problems, the present invention is capable of forming a fine SiO ₂ pattern having a high T _g and heat resistance with high precision by alkali development.
An object of the present invention is to provide a silicon composition having excellent transparency in a pUV region, and a pattern forming method using the composition.

Another object of the present invention is to provide a method of manufacturing an electronic component that performs fine processing with high accuracy using the obtained pattern.

[0009]

In order to solve the above-mentioned problems, the present invention provides a silicon compound having a hydrogensilsesquioxane structure, a compound capable of being decomposed by an acid to generate an acid, and a light irradiation method. A silicon composition characterized by containing a compound that generates an acid. Further, the present invention provides a silicon composition comprising a silicon compound having a hydrogen silsesquioxane structure represented by the following general formula (1) and a compound that generates an acid upon irradiation with light. I do.

[0010]

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(In the general formula (1), R ¹ represents a group capable of decomposing with an acid to form an acid, and m and n are natural numbers.) Further, the present invention provides a film containing the above-mentioned silicon composition. Forming a film on a substrate, irradiating a predetermined area of the silicon composition film with light, and exposing the exposed area of the silicon composition film after the exposure, dissolving and removing the exposed portion of the silicon composition film with an alkaline aqueous solution. And developing the pattern.

The present invention further provides a step of forming a film containing a carbon-based compound on a substrate, a step of forming a film containing the above-mentioned silicon composition on the carbon-based compound film, Irradiating a predetermined region of the material film with light to perform exposure, and dissolving and removing an exposed portion of the silicon composition film after the exposure with an alkaline aqueous solution to form a patterned silicon composition film And a step of transferring a pattern to a carbon-based compound film using the patterned silicon composition film as an etching mask.

The present invention also provides a step of forming a film containing the above-mentioned silicon composition on a substrate, a step of irradiating a predetermined region of the silicon composition film with light and exposing the same, A step of forming a patterned silicon composition film by dissolving and removing the exposed portion of the silicon composition film with an aqueous alkali solution to form a silicon composition film pattern; and a step of subjecting the silicon composition film pattern to a heat treatment to obtain a silicon oxide film pattern And a step of transferring the pattern to a substrate using the obtained silicon oxide film pattern as an etching mask.

Hereinafter, the present invention will be described in detail.

In the silicon composition of the present invention, the compound having a hydrogensilsesquioxane structure includes
Various hydridosilane resins represented by the following general formula (2) are exemplified.

[0016]

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In the above formula (2), R ² is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group; a halogen-substituted alkyl group such as a trifluoropropyl group; An alkyl group substituted with an ether group such as a group; selected from the group consisting of a substituted or unsubstituted phenyl group, a naphthyl group and an anthranyl group. Also, x, y and z are x = 0 to 2, y =
0 to 2, z = 1 to 3 and an integer satisfying x + y + z = 3.

Further, these resins have film properties, photoreactivity,
Other siloxane resin components may be included to improve the solubility of the aqueous alkali solution. Examples of the siloxane resin component that can be included include, for example, the following.

[0019]

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Compounds having a hydrogensilsesquioxane structure as described above are described, for example, in US Pat.
14, 272. Specifically, it is obtained by first hydrolyzing trichlorosilane using benzenesulfonic acid hydrate as a catalyst to obtain a resin component, and washing the resin component with water or an aqueous solution of sulfuric acid. Generally, it is obtained by hydrolyzing and condensing silane represented by HSiR ³ ₃ (R ³ represents a hydrolyzable group). When these are completely hydrolyzed, a resin represented by (HSiO _3/2 ) _n is obtained.
Condensation is insufficient and partially Si-O-R ³ group may remain.

The compounds having a hydrogensilsesquioxane structure other than the above-mentioned methods are also USP
5050159, USP 4999397, or EUP
The compound may be synthesized using the method described in U.S. Pat.

The molecular weight of the silicon compound is 200 or more and 1
It is preferably not more than 00,000, and not less than 200 and not more than 1
More preferably, it is not more than 000. Molecular weight 2
If it is less than 00, the durability of the formed film may decrease. On the other hand, if it exceeds 100,000, the solubility in an alkaline aqueous solution may decrease.

The amount of the silicon compound is preferably 1 to 99 parts by weight based on the whole composition. If the amount is less than 1 part by weight, it is difficult to sufficiently obtain the effect of blending the silicon compound, while if it exceeds 99 parts by weight, there is a possibility that a selective ratio of solubility may not be obtained.

In the present invention, examples of the compound which is decomposed by an acid to generate an acid (hereinafter, referred to as a dissolution inhibitor) include a compound represented by the following general formula (3).

[0025]

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In the above general formula (3), R ¹¹ is selected from the group consisting of a substituted or unsubstituted aliphatic group and a substituted or unsubstituted aromatic group, and Y ¹¹ is COO, OCO, S
O, OCOO, OCH ₂ COO or O;
¹² is a substituted or unsubstituted aliphatic group, wherein a beta carbon is substituted with hydrogen. Specific examples of R ¹¹ include the following groups.

[0027]

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[0028]

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[0029]

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Further, as R ¹² , the following groups are preferable because they decompose in the presence of an acid and become alkali-soluble after decomposition.

[0031]

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The compound represented by the general formula (3) undergoes the following reaction due to the presence of an acid.

[0033]

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R ¹¹ -Y ¹¹ H generated by this reaction exhibits alkali solubility. Examples of the compound represented by R ¹¹ -Y ¹¹ H include polyvinyl phenol resin, phenol novolak resin, cresol resin, xylesol resin,
Examples include phenol, naphthol, hydroxyanthracene, polymethacrylate, polyacrylate, benzoic acid, phenolphthalein, and silanol containing siloxane.

Examples of the dissolution inhibitor which can be used in the present invention include the following compounds.

[0036]

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[0037]

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[0038]

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[0039]

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The compounding amount of the dissolution inhibitor is preferably 1 to 50 parts by weight, more preferably 3 to 30 parts by weight, based on the silicon compound having a silsesquioxane structure. If the amount is less than 1 part by weight, the solubility of the unexposed part increases, so that the resolution tends to decrease,
On the other hand, when the amount exceeds 50 parts by weight, a resist residue is liable to be generated, and a decrease in coating film performance and film strength tends to be caused.

In the composition of the present invention, not only a compound capable of decomposing by an acid to generate an acid as described above is added as a dissolution inhibitor, but also a polymer of a silicon compound having a hydrogensilsesquioxane structure. A substituent having a dissolution inhibiting effect may be introduced into the main chain for use. Specific examples of the silicon compound include a compound represented by the following general formula (1).

[0042]

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Here, R ¹ is a group capable of decomposing in the presence of an acid to generate an acid (hereinafter referred to as a dissolution inhibiting group).
And n are integers. The dissolution inhibiting group is represented by the following general formula (4).

[0044]

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Here, R ²¹ is selected from the group consisting of a substituted or unsubstituted aromatic group and a substituted or unsubstituted aliphatic group, and Y ²¹ is COO, OCO, SO ₃ , OCO
O, OCH ₂ COO or O, and R ²² is a substituted or unsubstituted aliphatic group, wherein a beta carbon is substituted with hydrogen. Specifically, R ²¹ is the same group as R ¹¹ in the dissolution inhibitor described above, and R ²² is the same group as R ¹² described above.

Even in such a dissolution inhibiting group, the presence of an acid causes the same reaction as in the case of the dissolution inhibiting agent described above,
Portion of the reaction product (-R ²¹ -Y ²¹ H) exhibits alkali solubility.

Here, examples of silicon compounds having a hydrogen silsesquioxane structure into which a dissolution inhibiting group has been introduced are shown below.

[0048]

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In the equation, m, n, and k are natural numbers.

As in the case of the above-mentioned silicon compound having a hydrogensilsesquioxane structure, these resins contain other siloxane resin components in order to improve film properties, photoreactivity, and solubility in an aqueous alkaline solution. Alternatively, the hydrogen atom of Si—H may be partially substituted with an alkyl group or an aromatic group.

The compound having a hydrogensilsesquioxane structure represented by the general formula (1) can be synthesized, for example, according to the procedure described in US Pat. No. 3,615,272. Specifically, first, a resin component is obtained by hydrolyzing trichlorosilane, alkyltrichlorosilane and aromatic-substituted trichlorosilane using benzenesulfonic acid hydrate as a catalyst, and the resin component is obtained by washing with water or an aqueous sulfuric acid solution. Can be In general, silane represented by HSiR ³ ₃ or R ⁴ SiR ³ ₃ (R ³ represents a hydrolyzable group, and R ⁴ represents a substituted or unsubstituted aliphatic group or aromatic group) , By condensation. If these are completely hydrolyzed, it becomes a resin represented by (HSiO _3/2 ) _n ,
Condensation may be insufficient and Si-OR ⁴ may partially remain.

In addition to the methods described above, compounds having a repeating unit represented by the general formula (1)
SP5010159, USP4999397, EUP0
443760 may be used. Furthermore, the terminal of the obtained compound may be SiOH.

However, in the silicon compound having a hydrogensilsesquioxane structure represented by the general formula (1), the unit into which the dissolution inhibiting group R ¹ is introduced is preferably from ¹ to 50 in the compound. It is preferable that at least one structural unit exhibiting alkali solubility to which ^one R ¹ has not been introduced is present. When the number of structural units having alkali solubility is less than 1, it is difficult to dissolve in an alkaline aqueous solution. If the proportion of the dissolution inhibiting group is less than 1, there is a possibility that a sufficient dissolution inhibiting effect may not be obtained.

In the present invention, even when a silicon compound having a hydrogen silsesquioxane structure into which a dissolution inhibiting group is introduced as described above is used, the dissolution inhibitor described above may be further added.

In this case, it is preferable to select the compounding amount of the dissolution inhibitor so that the total amount of the dissolution inhibiting groups in the composition is from 1 to 50 based on silsesquioxane.

The two types of silicon compounds which can be incorporated in the composition of the present invention have been described above. Since both have a hydrogensilsesquioxane structure, the composition of the composition in which another silicon compound is incorporated is described. All the problems were solved, and a silicon composition having excellent characteristics was obtained.

The present inventors have found the following phenomenon with respect to a mixture of a silicon compound having a hydrogensilsesquioxane structure and a compound which is decomposed by an acid to generate an acid. That is, a film containing such a mixture is originally insoluble in an aqueous alkali solution, but an organic substance containing a silicon compound having a hydrogensilsesquioxane structure and an acid is alkali-soluble. Therefore, by further compounding a compound that generates an acid upon irradiation with light, it was possible to obtain a silicon composition capable of forming a positive pattern by selectively exposing exposed portions to alkali solubility.

In general, a silicone resin having a siloxane bond cannot maintain a pattern because the Tg decreases when an alkyl substituent is introduced. It has been attempted to introduce an aromatic substituent such as a benzene ring for the purpose of increasing Tg. However, the aromatic substituent has poor transparency in the deep UV region, and has a high Tg and transparency in the deep UV region. I could not be satisfied.

The silicon compound having a hydrogensilsesquioxane structure has a Tg in addition to the above-mentioned properties.
And the transparency is good in the deep UV region. Therefore, by using a composition containing this silicon compound, a pattern having excellent heat resistance and good shape can be formed. Note that de
In consideration of the transparency to the epUV region, it is more preferable to introduce an aliphatic carboxylic acid derivative than to introduce an aromatic substituent. Further aliphatic carboxylic acid derivative is introduced hydrogen silsesquioxane structure, even when a SiO ₂ film by firing, it is convenient because scattering organic components at a lower temperature.

In the present invention, the compound capable of generating an acid upon irradiation with actinic radiation (hereinafter referred to as an acid generator) includes, for example, onium salts, halogen-containing compounds, quinonediazides, sulfone compounds, sulfonic acid compounds and nitribenzyl compounds. Is mentioned. Onium salts include sulfonium salts, iodonium salts, and diazonium salts. The sulfonium salt is a compound represented by the general formula (AG).

[0061]

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(Here, R ²¹ , R ²² and R ²³ may be the same or different from each other, and each represents a substituted or unsubstituted group having a halogen atom, an ether bond, a thioether bond, a cyano group, an amino group or an ester bond. And X represents BF ₄ , As
_{F 6, PF 6, SbF 6} , CF 3 SO 3, substituted or unsubstituted aromatic represents such SO ₃ substituted. More specifically, the following compounds are exemplified.

[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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The iodonium salt is represented by the general formula (DG).

[0070]

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(Here, R ²⁴ and R ²⁵ may be the same or different from each other, and each represents a substituted or unsubstituted aromatic group having a halogen atom, an ether bond, a thioether bond, a cyano group, an amino group, or an ester bond. X represents BF ₄ , AsF ₆ , P
_{F 6, SbF 6, CF 3} SO 3, substituted or unsubstituted aromatic represents such SO ₃ substituted. Specific examples include the following compounds.

[0072]

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[0073]

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The diazonium salt is represented by the general formula (EG).

[0075]

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(Where R ²⁶ represents a substituted or unsubstituted aromatic or aliphatic group having a halogen atom, an ether bond, a thioether bond, a cyano group, an amino group or an ester bond. X is BF ₄ , AsF ₆ , PF
_{6, SbF 6, CF 3 SO} 3, substituted or unsubstituted aromatic represents such SO ₃ substituted. Specific examples include the following compounds.

[0077]

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Examples of the halogen-containing compound include a haloalkyl group-containing hydrocarbon compound and a haloalkyl group-containing heterocyclic compound. Specific examples are shown below.

[0079]

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[0080]

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[0081]

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Specific examples of the quinonediazide compound include diazonaphthoquinone, diazobenzoquinone and ketone types. Specific examples are shown below.

[0083]

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In the formula, NA represents naphthoquinonediazide.

Examples of the sulfone compound include beta keto sulfone and beta sulfonyl sulfone, and specific examples are shown below.

[0086]

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[0087]

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Examples of the nitrobenzyl compound and sulfonic acid compound include orthonitrobenzylsulfonic acid, alkylsulfonic acid ester, arylsulfonic acid ester, and iminosulfonate. Specific examples are shown below.

[0089]

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[0090]

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[0091]

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[0092]

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[0093]

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[0094]

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The amount of such an acid generator is preferably 0.1 to 30 parts by weight, more preferably 1 to 10 parts by weight, based on the silicon compound having a hydrogensilsesquioxane structure. If the amount of the acid generator is less than 0.1 part by weight, the amount of the acid generated upon exposure is small, and the reaction may not sufficiently occur. On the other hand, when the amount of the acid generator exceeds 30 parts by weight, film properties such as strength and flatness deteriorate.

In addition to the above-described components, the silicon composition of the present invention may contain other silicon compounds, and specific examples include the following compounds.

[0097]

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When such a silicon compound is compounded, it is preferable that the compounding amount is about 100 parts by weight or less based on 100 parts by weight of the basic silicon compound.
If it exceeds 100 parts by weight, the solubility in an alkaline aqueous solution may be reduced.

Further, a base or a weak base may be added in order to enhance environmental stability as used for a general chemically amplified resist. Specific examples of the basic compound include:
For example, a pyridine derivative, t-butylpyridine,
Acid generation of benzylpyridine, pyridinium salts and the like, and aniline derivatives which are aromatic amines such as N-methylaniline, N-ethylaniline, N ′, N-dimethylaniline, diphenylamine, N-methyldiphenylamine, indene, etc. 0.1-50 mol% of the agent,
Further, it is preferable to add 1 to 15 mol%. 0.
If the amount is less than 1 mol%, the effect of adding the basic substance cannot be sufficiently obtained, while if it exceeds 50 mol%, the inherent sensitivity of the resist is significantly reduced.

The silicon composition of the present invention is prepared by dissolving a silicon compound having a hydrogensilsesquioxane structure as described above, an acid generator and, if necessary, a dissolution inhibitor in an organic solvent. Can be. Examples of the organic solvent that can be used here include, for example, toluene, xylene, dimethylformamide, dimethylacetamide,
Examples include aromatic hydrocarbons such as methyl cellosolve, methyl isobutyl ketone, ethyl lactate, and dimethyl siloxane, alkanes, siloxanes, ethers, ketones, and ester solvents. These can be used alone or in the form of a mixture.

Next, a pattern forming method using the silicon composition of the present invention will be described.

First, the silicon composition prepared as described above is applied on a predetermined substrate, and heated at 50 to 150 ° C., preferably 50 to 100 ° C. by a hot plate.
It is dried at a temperature of about ℃ to evaporate the organic solvent to some extent to form a silicon composition film. As a method for applying the solution containing the silicon composition, spin coating, dip coating, spray coating, flow coating, or the like can be employed. The thickness of the silicon composition film obtained here can be appropriately determined depending on the solution concentration, coating conditions, and the like. For example, when a 5% solution is applied by spin coating at 2,000 rpm, the thickness is 0.1 to 0.1%. It can be about 0.2 μm. Further, as the substrate, for example, a silicon wafer; a silicon wafer having various insulating films, electrodes, wirings, etc. formed on the surface; a blank mask; GaAs, AlG
III-V compound semiconductor wafers such as aAs; chromium or chromium oxide deposition mask; aluminum deposition substrate; IBPS
G-coated substrate; PSG-coated substrate; SOG-coated substrate;
A carbon film sputtered substrate or the like can be used.

Next, the silicon composition film is exposed to actinic radiation through a photomask having a predetermined pattern, or is directly scanned with the actinic radiation on the surface of the silicon composition film, to thereby perform pattern exposure on the silicon composition film. As actinic radiation here,
Visible light, ultraviolet light, X-rays, electron beams, ion beams, and the like can be used.
Particularly effective for ultraviolet rays, high-pressure mercury lamp, low-pressure mercury lamp, medium-pressure mercury lamp, xenon lamp, Ar
Excimer laser light such as F, KrF, Xe, or Kr can be used as an exposure source.

After the exposure, if necessary, the temperature is 50 ° C. or more and 150
A post-exposure bake for 10 seconds or more and 10 minutes or less at a temperature of not more than ° C. may be used to promote the acid-catalyzed reaction.

Here, in the exposed portion of the silicon composition film, the dissolution inhibiting group is decomposed by the action of the acid generated from the acid generator and is solubilized in the alkaline aqueous solution. Thus, the exposed portion of the silicon composition film is selectively dissolved and removed, and a positive pattern is formed. At this time, as the alkaline aqueous solution, an organic alkaline aqueous solution such as tetramethylammonium hydroxide or choline or an inorganic aqueous solution such as potassium hydroxide or sodium hydroxide may be used, and a method such as a dipping method or a spray method may be employed. it can.

It is desired that the resulting pattern be sufficiently washed to remove the developing solution components. Finally, the temperature of the pattern is gradually raised, and the pattern is heated at 200 ° C. to 1000 ° C. to obtain a patterned SiO ₂ film.

The thus-obtained patterned SiO
_{The two} films are excellent in heat resistance, insulating properties, and the like, and can be suitably used as an insulating film or a protective film of a semiconductor device, and further, as an etching mask when etching a substrate. Further, the silicon composition film pattern before heating can be used as an etching mask for transferring the pattern to the carbon film by reactive ion etching using oxygen.

Furthermore, the silicon composition of the present invention contains a silicon compound having a hydrogensilsesquioxane structure as a main component, and a group having a dissolution inhibiting action is introduced into this compound, or a dissolution inhibitor is added to the compound. Since it contains a photoacid generator, it is possible to form an ultrafine pattern with extremely high resolution by developing with an aqueous alkali solution.

Here, a method for manufacturing an electronic component according to the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing one example of a manufacturing process of the electronic component of the present invention. First, as shown in FIG. 1A, a film 12 containing the silicon composition of the present invention is formed on a silicon substrate 11 and irradiated with exposure light 14 via a mask 13 having a predetermined pattern.

Next, after heat treatment as needed, the exposed portion of the silicon composition film is selectively dissolved and removed by developing with an alkaline aqueous solution, and the silicon composition film patterned as shown in FIG. A film 15 is obtained. After development, heat treatment is performed at about 100 to 500 ° C. for about 1 to 10 minutes to form a silicon oxide film pattern.

By etching the substrate using the silicon oxide film pattern thus obtained as an etching mask, the pattern can be faithfully transferred as shown in FIG. 1 (c). As an etching method at this time, for example, a wet etching method or a dry etching method is adopted, but when a fine pattern of 3 μm or less is formed, the dry etching method is preferable. Examples of the wet etching agent include a hydrofluoric acid aqueous solution and an ammonium fluoride aqueous solution when a silicon oxide film is to be etched, and a phosphoric acid aqueous solution, an acetic acid aqueous solution, and a nitric acid aqueous solution when aluminum is to be etched.
When a chromium-based film is to be etched, a cerium ammonium nitrate aqueous solution or the like is used. Examples of dry etching gas include CF ₄ , C ₂ F ₆ , CCl ₄ ,
Examples include BCl ₃ , Cl ₂ , HCl and H ₂ . These gases are used in combination as needed. As the etching conditions, the concentration of the wet etching agent in the reaction tank, the concentration of the gas for dry etching, the reaction temperature, the reaction time, and the like are determined based on the film thickness, the film composition, and the like, but are not particularly limited to the method and the like. .

After the etching as described above, the silicon oxide film pattern used as the etching mask has excellent strength, heat resistance and the like, and can be used as it is as an insulating film or the like.

The silicon composition of the present invention can be applied to a two-layer resist system to produce electronic parts.
FIG. 2 is a cross-sectional view illustrating an example of a manufacturing process of the electronic component in this case.

First, as shown in FIG. 2A, a carbon film 22 and a film 23 containing the silicon composition of the present invention are sequentially formed on a substrate 21 to be finely processed. The carbon film may be any of inorganic carbon, organic compounds and organic polymers,
Specific examples include a polymer layer, a polyimide layer, and an inorganic carbon layer obtained by baking a resist film containing a novolak resin and naphthoquinonediazide. These carbon films can be easily formed by any film forming technique such as a spin coating method, a CVD method, and a sputtering method.
Further, the thickness of the carbon film is usually formed in the range of 0.1 μm to 2 μm.

The thickness of the film containing the silicon composition of the present invention formed on the carbon film 22 is usually 0.05 μm to 1 μm.
Is within the range. After irradiating the silicon composition film 23 with exposure light 25 through a mask 24 having a predetermined pattern, the silicon composition film 23 is subjected to a heat treatment if necessary, and developed with an alkaline aqueous solution, so that an exposed portion of the silicon composition film is exposed. It is selectively dissolved and removed to obtain a patterned silicon composition film 26 as shown in FIG. As described above, after the development, heat treatment may be performed by heating at about 100 to 500 ° C. as necessary.

The above-described exposure, development, and heat treatment steps may be performed in any atmosphere in which oxygen is present or in an inert gas such as nitrogen or argon.

Next, the formed silicon composition film pattern 2
6 is used as an etching mask, the exposed carbon film is etched using oxygen gas plasma or an appropriate solvent.
At this time, oxygen reactive ion etching (oxygen RIE) using oxygen gas plasma is more preferable, and is usually 10 to 100 Torr and 50 to 400 w /.
Treat in cm ² for 1-10 minutes. Here, the pattern formed using the silicon composition of the present invention is subjected to anisotropic reactive ion etching containing oxygen, so that silicon dioxide (SiO ₂ ) or a film similar thereto is formed on the surface, It has oxygen RIE resistance 2 to 50 times that of the exposed carbon layer. For this reason, the carbon layer portion exposed from the pattern is selectively removed by oxygen RIE.
As shown in (c), a patterned carbon film 27 is obtained.

Silicon oxide film pattern 2 thus obtained
6 and the carbon film pattern 27 as an etching mask, the pattern is faithfully transferred by etching the substrate 21 by the method described above, and FIG.
A finely processed substrate 28 as shown in FIG.

After the etching, the carbon film 22 and the silicon oxide film pattern 26 remaining on the substrate are
By removing with a release agent such as hydrofluoric acid or an organic solvent, oxygen gas plasma, or the like, a finely processed substrate shown in FIG. 2E is obtained.

In addition to the above steps, any additional steps may be added according to the purpose. For example,
For the purpose of improving the adhesion between the film containing the silicon composition of the present invention and the carbon film or between the carbon film and the substrate, a pretreatment step or the like performed before the application of each liquid can be mentioned.

[0122]

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example I An acid generator and a dissolution inhibitor were added to a silicon compound having a hydrogensilsesquioxane structure to prepare a silicon composition of the present invention.

As the silicon compound, the following chemical formula (Si1
Polyhydrogensilsesquioxane having a repeating unit represented by 1) was used. This compound was synthesized as follows.

[0125]

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First, a hydrogen silsesquioxane resin was prepared by the method described in JP-B-47-31838. To a mixture of 3.75 mol of sulfuric acid and 2.25 mol of fuming sulfuric acid, 6 mol of toluene was added dropwise over 1 hour at a liquid temperature of 45 to 60 ° C., and further heated at 45 ° C. for 30 minutes. Sulfonic acid monohydrate was obtained. There,
At 30 ° C., a mixture of 1 mol of trichlorosilane and 6.6 mol of toluene was added dropwise over 5 hours, and the mixture was further heated at 45 ° C. for 30 minutes. After cooling and liquid separation, the lower toluene sulfonic acid layer was removed, and then washed with an appropriate amount of sulfuric acid / water (50/50 weight ratio) in order to remove the acid contained in the upper layer. Washing was performed with water (25/75 weight ratio) and pure water. Next, an azeotropic dehydration is performed to remove water.
Time went on. The toluene solution thus obtained was depressurized with a vacuum pump at 60 ° C. to remove toluene, thereby preparing hydrogen silsesquioxane resin A. This hydrogen silsesquioxane resin A had a number average molecular weight (hereinafter abbreviated as Mn) of 1650, and a weight average molecular weight / number average molecular weight (hereinafter abbreviated as Mw / Mn) of 19.4. .

Subsequently, a sufficiently dried high-grade glass 1
20 g of hydrogen silsesquioxane resin A was placed in a liter flask, and 80 g of sufficiently dehydrated toluene was added to dissolve sufficiently. The entire system was kept at 25 ° C., and the inside of the system was purged with nitrogen to such an extent that the solvent did not fly outside the system, and the purging was continued until the separation was completed. Keep the solution under vigorous stirring
g of fully dehydrated acetonitrile was added dropwise over 1 hour. After standing for about 12 hours, the sediment was removed. Next, 200 g of sufficiently dehydrated acetonitrile was added dropwise to the solution from which the precipitate had been removed over 4 hours. The resulting precipitate was collected, and the remaining solvent was removed by vacuum drying at room temperature to prepare hydrogen silsesquioxane resin B. Mn of this hydrogen silsesquioxane resin B is 114
00 and Mw / Mn were 2.88, and ionic impurities and metal impurities were each 1 ppm or less.

The acid generator and dissolution inhibitor used here are shown below with their abbreviations.

[0129]

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[0130]

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Each of the above components was blended according to the formulation shown in Table 1 below, and dissolved in methyl isobutyl ketone as a solvent.
Examples (I-1) to (I-5) and Comparative Example (I-1)
Was prepared.

[0132]

[Table 1]

In Table 1, numerical values in parentheses indicate the amounts (parts by weight).

Each composition was applied on a substrate by spin coating, exposed and developed to form a pattern, and the resolution of the obtained pattern was examined. The results are summarized in Table 2 below together with various conditions for pattern formation.

[0135]

[Table 2]

In Table 2, TMAH represents an aqueous solution of tetramethylammonium hydroxide.

As shown in Table 2 above, a pattern could not be formed only with hydrogensilsesquioxane (Comparative Example I-1), but an acid generator and a dissolution inhibitor were blended. Compositions of the Invention (Examples I-1 to I-1)
In each of I-5), a fine pattern having a line width of 0.35 μm or less could be formed. In particular, in the case of the composition of Example (I-2) in which the compound (S2) is used as an acid generator and the compound (Y2) is used as a dissolution inhibitor, an ArF excimer laser beam is irradiated at an exposure amount of 50 mJ. Indicates that a pattern having a line width of 0.2 μm is formed, and it can be seen that the pattern can be formed with extremely high resolution.

Next, the embodiments (I-1) to (I-
The composition of 5) was applied to a two-layer resist, and the pattern was transferred to the lower layer. Specifically, first, polyimide was applied on a substrate, and heated at 200 ° C. for 30 minutes to form a carbon-based film having a thickness of 1.0 μm. Furthermore, after forming a film containing the silicon composition of the present invention in the same manner as described above, patterning was performed under the same conditions to form a silicon film pattern.

Using the obtained silicon film pattern as an etching mask, the carbon-based film was etched at 1000 W RF plasuma discharge under 2.2 Torr of oxygen. Table 3 below summarizes the size of the pattern transferred to the carbon-based film together with the size of the silicon film pattern.

[0140]

[Table 3]

As shown in Table 3, when the composition of the present invention was used, the pattern of the silicon layer could be transferred onto the carbon film with good reproducibility.

Further, the above-mentioned embodiments (I-1) to (I-
Each of the compositions 5) was applied to a substrate by spin coating to form a 2 μm-thick silicon composition film. This is carried out at 100 ° C. for 10 minutes, at 200 ° C. for 30 minutes, and at 300 ° C. for 30 minutes.
And cured at 500 ° C. for 3 hours, and the insulation resistance value of the obtained film was measured. As a result, each of the films had an insulation resistance value of 10 ¹⁵ Ω · cm, and it was confirmed that the films had excellent insulation properties.

(Example II) First, a silicon compound having a hydrogensilsesquioxane structure was synthesized by introducing a group capable of decomposing with an acid to generate an acid as follows.

Hydrogenzyl sesquioxane 10 g
Was dissolved in 100 ml of dibutyl ether, and 4 g of a compound represented by the following chemical formula and 0.1 g of a platinum catalyst were added thereto.

[0145]

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This mixed solution was reacted at 50 ° C. for 3 hours to obtain a silicon compound represented by the following chemical formula (Si1). The weight average molecular weight of the obtained compound is 100
It was 0.

[0147]

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Further, a silicon compound represented by the following chemical formula (Si2) was obtained by hydrolyzing triethoxysilane and a compound represented by the following chemical formula with an alkali catalyst. The weight average molecular weight of the obtained compound is 1
500.

[0149]

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[0150]

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The silicon compound thus obtained (Si
1, Si2), an acid generator and a dissolution inhibitor were blended according to the formulation shown in Table 4 below and dissolved in methyl isobutyl ketone as a solvent. Examples (II-1) to (II-5) and Comparative Examples The composition of Example (II-1) was prepared. The acid generators (S1 to S5) and the dissolution inhibitor (Y
5) is the same compound as used in the above (Example I).

[0152]

[Table 4]

In Table 4, the values in parentheses indicate the amounts (parts by weight).

Each composition was applied on a substrate by spin coating, exposed and developed to form a pattern, and the resolution of the obtained pattern was examined. The results are summarized in Table 5 below together with various conditions for pattern formation.

[0155]

[Table 5]

In Table 5, TMAH represents an aqueous solution of tetramethylammonium hydroxide.

As shown in Table 5 above, a pattern could not be formed only with hydrogensilsesquioxane (Comparative Example II-1), whereas an acid generator and, if necessary, a dissolution inhibitor were used. All of the compositions of the present invention (Examples II-1 to II-5) were able to form a fine pattern having a line width of 0.35 μm or less. In particular, in the case of the composition of Example (II-2) in which the compound (S2) is used as an acid generator and the compound (Y2) is used as a dissolution inhibitor, an ArF excimer laser beam is irradiated at an exposure amount of 50 mJ. As a result, a pattern having a line width of 0.2 μm was formed, indicating that the pattern could be formed with high resolution.

Next, the above Examples (II-1) to (II-
The composition of 5) was applied to a two-layer resist, and the pattern was transferred to the lower layer. Specifically, first, OFBR800 manufactured by Tokyo Ohka Co., Ltd. was applied on the substrate and baked at 250 ° C. for 10 minutes to form a carbon-based film having a thickness of 1.0 μm. Furthermore, after forming a film containing the silicon composition of the present invention in the same manner as described above, patterning was performed under the same conditions to form a silicon film pattern.

Using the obtained silicon film pattern as an etching mask, the carbon-based film was etched at 1000 W RF plasuma discharge under 2.2 Torr of oxygen. Table 6 below summarizes the size of the pattern transferred to the carbon-based film together with the size of the silicon film pattern.

[0160]

[Table 6]

As shown in Table 6, when the composition of the present invention was used, the pattern of the silicon layer could be transferred onto the carbon layer with good reproducibility.

Further, in the above-mentioned Examples (II-1) to (II-
Each of the compositions 5) was applied to a substrate by spin coating to form a 2 μm-thick silicon composition film. This is carried out at 100 ° C. for 10 minutes, at 200 ° C. for 30 minutes, and at 300 ° C. for 30 minutes.
And cured at 500 ° C. for 3 hours, and the insulation resistance value of the obtained film was measured. As a result, each of the films had an insulation resistance value of 10 ¹⁵ Ω · cm, and it was confirmed that the films had excellent insulation properties.

Example III First, the compound (Si
In the same manner as in 1), a silicon compound represented by the following chemical formula was synthesized. The weight average molecular weight of the obtained compound was 1500.

[0164]

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99 parts by weight of this silicon compound and 1 part by weight of a compound represented by the following chemical formula as an acid generator were dissolved in 900 parts by weight of butyl ethyl ketone to obtain a solution containing the silicon composition of the present invention. .

[0166]

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This solution was applied on a silicon wafer by spin coating and baked at 100 ° C. for 1 minute to form a film having a thickness of 0.1 μm.
A 1 μm silicon composition film was formed. Next, the silicon composition film was exposed to ArF excimer laser light at an exposure of 10 mJ / cm ² through a mask having a predetermined pattern, and then baked at 100 ° C. for 2 minutes. Thereafter, development was carried out with a 2.38% aqueous solution of tetramethylammonium hydroxide at room temperature for 1 minute to obtain a silicon oxide film pattern having a line width of 0.15 μm.

The obtained silicon oxide film pattern was heated at 250 ° C.
After baking for 5 minutes at 35 SCCM, 25 mTorr
When a silicon wafer was etched by applying a bias of r and 20 V, a pattern of 0.15 μm was transferred to the silicon wafer.

[0169]

As described in detail above, according to the present invention,
A fine SiO ₂ film pattern having a high T _g and heat resistance can be formed accurately by alkali development,
Moreover, a silicon composition having excellent transparency in the deep UV region is provided. A pattern formed using such a silicon composition can be applied not only as an etching mask when performing microfabrication on an underlayer such as a substrate, but also as an insulating film or a protective film, and its industrial value There is a great thing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a manufacturing process of an electronic component according to the present invention.

FIG. 2 is a sectional view showing another example of the manufacturing process of the electronic component according to the present invention.

[Explanation of symbols]

 11, 21 ... silicon substrate 12, 23 ... silicon composition film 13, 24 ... mask 14, 25 ... exposure light 15, 26 ... patterned silicon composition film 16, 28 ... finely processed substrate 22 ... carbon film 27 … Patterned carbon film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihiko Nakano 1 Toshiba R & D Center, Komukai-shi, Kawasaki City, Kanagawa Prefecture (72) Inventor Yasuhiko Sato Toshiba Komukai, Sachi-ku, Kawasaki City, Kanagawa Prefecture No. 1 town Toshiba R & D Center

Claims (5)

[Claims] 1. A silicon composition comprising: a silicon compound having a hydrogensilsesquioxane structure; a compound capable of decomposing with an acid to generate an acid; and a compound generating an acid by irradiation with light. Stuff. 2. A silicon compound having a hydrogen silsesquioxane structure represented by the following general formula (1):
A compound comprising a compound that generates an acid upon irradiation with light. Embedded image (In the general formula (1), R ¹ represents a group which can be decomposed by an acid to generate an acid, and m and n are natural numbers.) 3. A step of forming a film containing the silicon composition according to claim 1 on a substrate, and a step of irradiating a predetermined region of the silicon composition film with light to perform exposure. And dissolving and removing exposed portions of the exposed silicon composition film with an aqueous alkali solution to develop the exposed portions. 4. A step of forming a film containing a carbon-based compound on a substrate, a step of forming a film containing the silicon composition according to claim 1 on the carbon-based compound film, A step of irradiating a predetermined region of the silicon composition film with light to perform exposure, and a step of dissolving and removing an exposed portion of the silicon composition film after the exposure with an alkaline aqueous solution to develop the patterned silicon composition. A pattern forming method, comprising: forming a film; and transferring a pattern to a carbon-based compound film using the patterned silicon composition film as an etching mask. 5. A step of forming a film containing the silicon composition according to claim 1 or 2 on a substrate, a step of irradiating a predetermined region of the silicon composition film with light and exposing the same, A step of dissolving and removing the exposed portion of the silicon composition film after the exposure with an alkaline aqueous solution and developing the silicon composition film to form a patterned silicon composition film; and heat treating the silicon composition film pattern to form a silicon oxide film. A method for manufacturing an electronic component, comprising: a step of obtaining a pattern; and a step of transferring a pattern to a substrate using the obtained silicon oxide film pattern as an etching mask.